Water/Environment Best Project - Tempe Town Lake Downstream Dam Replacement
Tempe Town Lake Downstream Dam Replacement
Owner/Developer City of Tempe
General Contractor PCL Construction Inc.
Lead Design Firm Gannett Fleming Inc.
Civil Engineer Gannett Fleming Inc.
Subcontractors Action Equipment and Scaffolding; All Metal Specialties; Arizona Dept. of Water Resources; Blount Contracting; CEMEX Construction Materials; Gerdau Reinforcing Steel; Hark Drilling; Harrington Industrial Plastics; K&F Electric; Kimley-Horn and Associates; MKB Construction; Municipal Treatment Equipment; OPT CO; PDC Testing Services; Polyset; Rodney Hunt-Fontaine; Structural Grace; Western Concrete Plumbing.
After the original rubber-bladder dam failed in 2010 and drained 1 billion gallons of water without warning from Tempe Town Lake, the city of Tempe, Ariz., engaged the construction team to design and build a more permanent replacement. The new $45-million dam comprises eight hydraulically operated steel gates, each 106 ft wide, 17 ft tall and weighing 260,000 lb. The gates are supported by seven concrete piers that are 25 ft high and 9 ft wide, along with two abutments and a 21-ft-thick concrete foundation. Crews built 16 hydraulic rams, angled at 70 degrees, to support and operate the gates.
“The gates can lay flat in a major storm to drain [excess water] into the river,” says Chris Kabala, city of Tempe senior civil engineer.
Massachusetts-based Steel-Fab Inc. created the dam’s crest gates. For cost and logistical reasons, the company worked with Phoenix-based Schuff Steel to fabricate the eight massive gates locally while quality control and fabrication staff monitored the fabrication process.
Construction crews had to accommodate sudden monsoons, a levee system, recreation around the lake and challenging groundwater and geologic conditions.